Light modulator device

ABSTRACT

A light modulator device includes a top plate and an angled extender coupled to the top plate. The angled extender includes an incident portion and an exit portion that is relatively thicker than the incident portion.

BACKGROUND

Micro-electromechanical systems (MEMS) are used in a variety ofapplications, including optical display systems. In many optical displaysystems, arrays of MEMS devices commonly referred to as pixels areelectromechanically controlled to reflect image-carrying modulated lighttoward display optics for display. As a light source projects light raysonto the pixels, the pixels reflect modulated light rays carrying imagedata toward the display optics. The pixels may be electromechanicallycontrolled to regulate the characteristics of the modulated light. Forexample, some pixels include spatial gaps that are controlled todetermine the characteristics of the modulated light. For example, thespatial gap may be set to a distance that limits the reflected modulatedlight to a particular range of wavelengths.

As light rays from the light source reach the pixels, a certain amountof the light rays reflects off of the surfaces of the pixels and mixeswith the modulated light. For example, some types of pixels have apartially reflective top plate. The surface of the top plate of such apixel will reflect a portion of the light rays away from the pixel.Light that reflects off of pixel surfaces is commonly referred to asstray light. If the amount of stray light that mixes with the modulatedlight is high, the resulting display images will have poor contrast.

Stray light can also be introduced by other surfaces of optical displaysystems. In particular, any surface positioned between the light sourceand the pixels may reflect a portion of the light rays away from thepixels. For example, many optical display systems include a cover plateplaced over arrays of pixels to protect the pixels from harm. However,like the surfaces of the pixels, the surface of the cover plate tends toproduce stray light by reflecting some incident light rays away from thepixels. The light reflected off of the cover plate is also known asstray light and may mix with the modulated light. Consequently,conventional cover plates may degrade the contrast of display images.

One attempt to curtail the effects of stray light reflections from thesurfaces of pixels and cover plates includes the use of anti-reflectivecoating specifications for pixel surfaces and cover plates.Anti-reflective coatings on the surfaces of pixels and cover plates areused to reduce the reflection from these surfaces. However, the residualreflections from the anti-reflection coated surfaces still reduce thecontrast in modern high performance projector systems.

An approach for reducing the stray light even further includessuperimposing pixel arrays one over another. However, this approach isfrequently complicated and expensive to implement. Not only is the costof parts increased, the superimposed pixel arrays must be positioned andremain in proper alignment with each other for proper operation of thedisplay systems that make use of this approach.

SUMMARY

A light modulator device includes a top plate and an angled extendercoupled to the top plate. The angled extender includes an incidentportion and an exit portion that is relatively thicker than the incidentportion.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments of the presentapparatus and methods and are a part of the specification. Theillustrated embodiments are merely examples of the present apparatus andmethods and do not limit the scope of the disclosure.

FIG. 1 illustrates a block diagram of an exemplary display system,according to one embodiment.

FIG. 2 illustrates a schematic view of the display system of FIG. 1,according to one embodiment.

FIG. 3A illustrates a section view of an exemplary pixel having anangled extender, according to one embodiment.

FIG. 3B illustrates a perspective view of multiple exemplary pixels ofFIG. 3A arranged on an integrated circuit chip, according to oneembodiment.

FIG. 4 illustrates a section view of an exemplary cover plate positionedover a pixel, according to one embodiment.

FIG. 5 illustrates a section view of an exemplary segment of an array ofthe exemplary pixels of FIG. 3A covered by the cover plate of FIG. 4,according to one embodiment.

FIG. 6 is a flowchart illustrating an exemplary method of reducing straylight contribution to modulated light in the display system of FIG. 1,according to one embodiment.

FIG. 7 is a flowchart illustrating an exemplary method of forming anarray of exemplary pixels having the angled extenders of FIG. 3A,according to one embodiment.

Throughout the drawings, identical reference numbers designate similar,but not necessarily identical, elements.

DETAILED DESCRIPTION

An exemplary pixel is described herein. Accordingly to several exemplaryembodiments, the pixel includes an angled extender coupled to an uppersurface of a pixel. The angled extender of the exemplary pixel mayimprove the contrast of images produced by a display system by reducingthe amount of stray light contribution to the images. Stray light refersto portions of light projected from a light source that are undesirablyreflected off of the surfaces of pixels and/or other components of adisplay system. The angled extender of the exemplary pixel may bearranged to reduce the stray light contribution to display images byreflecting a portion of the light rays from a light source away from thepixel in a manner that separates the reflected light from the modulatedimage-carrying light generated by the pixel. Consequently, the amount ofstray light that mixes with the modulated light is reduced, and picturecontrast of the display system may be improved.

In several exemplary embodiments, an angled, wedge-shaped cover platemay be positioned between a pixilated integrated circuit chip and alight source of a display system. As light from the light source strikesthe surface of the cover plate, stray light reflects away from thepixels in a manner that separates the reflected light from the modulatedimage-carrying light produced by the pixels. Consequently, the amount ofstray light that mixes with display images is reduced, and picturecontrast of the display system may be improved. The cover plate may beimplemented in addition to or in lieu of the angled extenders of theexemplary pixels units.

Exemplary methods of using and forming the pixels are also describedherein. Arrays of exemplary pixels may be formed by attaching angledextenders to upper surfaces of the pixels of a pixilated chip using anindex-matching adhesive. In one exemplary embodiment, an array of angledextenders may be produced and indexed to match an array of pixels. Thearray of angled extenders may be attached to the pixels using anadhesive. A laser scribe may be used to isolate the angled extendersfrom each other either before or after affixation to the pixels.

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present methods and apparatus. It will be apparent,however, to one skilled in the art, that the present method andapparatus may be practiced without these specific details. Reference inthe specification to “one embodiment” or “an embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment is included in at least one embodiment. Theappearance of the phrase “in one embodiment” in various places in thespecification are not necessarily all referring to the same embodiment.

Display Systems

FIG. 1 illustrates an exemplary display system (100). The components ofFIG. 1 are exemplary only and may be modified or changed as best servesa particular application. As shown in FIG. 1, image data is input intoan image processing unit (110). The image data defines an image that isto be displayed by the display system (100). While one image isillustrated and described as being processed by the image processingunit (110), it will be understood by one skilled in the art that aplurality or series of images may be processed by the image processingunit (110). The image processing unit (110) may perform variousfunctions including controlling the illumination of a light source (120)and controlling a spatial light modulator (SLM) (130). The light source(120) may project light toward the SLM (130).

The SLM (130) may include one or more arrays light modulator devices.The light modulator devices may be in the form of micro-electromechanical (MEM) devices (not shown in FIG. 1), or pixels, which areconfigured to selectively modulate light and direct the modulated lighttoward a display (not shown), as discussed below. An angled extender maybe attached to an upper surface of each pixel. As light travels from thelight source (120) to a pixel, a certain amount of the light isreflected away from the pixel by the angled extender. The angledextender may be arranged so that the stray light reflected off of thesurface of the angled extender is separated from the modulated lightreflected by the pixel, as discussed in detail below.

The SLM (130) may include an angled, wedge-shaped cover plate to protectthe pixels. Similarly to the angled extenders of the pixels, the coverplate may be positioned between the pixels and the light source (120)such that the cover plate is configured to direct some of the lightreflected therefrom away from the modulated light reflected by thepixels. The cover plate may be implemented in the SLM (130) in additionto or in lieu of the angled extenders. The angled extenders and thecover plate will each be described in more detail below.

Returning to the operation of the display system (100) in general, theSLM (130) manipulates incoming light to form an image-bearing beam oflight, referred to as modulated light, that is eventually displayed orcast by display optics (140) on a viewing surface (not shown). The SLM(130) includes an array of individual pixels to generate an image.

The display optics (140) may comprise any device configured to displayor project an image. For example, the display optics (140) may be, butare not limited to, a lens configured to project and focus an image ontoa viewing surface. The viewing surface may be, but is not limited to, ascreen, television, wall, liquid crystal display (LCD), or computermonitor. The angled extenders and/or the angled cover plate discussedherein generally improve the contrast of images displayed by the displaysystem (100) by reducing the amount of stray light that travels from theSLM (130) to the display optics (140). In other words, the angledextenders and/or the angled cover plate improve the ratio of stray lightcontribution from the SLM (130). The stray light ratio is defined asimaging light divided by the stray light.

FIG. 2 illustrates a schematic view of the display system (100) in whichthe light source (120) directs light rays (210) at the SLM (130). TheSLM (130) reflects an image-bearing beam of light referred to asmodulated light (220) toward the display optics (140). As shown in FIG.2, the SLM (130) also reflects stray light (230) generally in adirection that prevents the stray light (230) from intersecting thedisplay optics (140). As a result, the amount of stray light (230) thatmixes with the modulated light (220) is minimized, thereby improving thecontrast of the displayed image.

Angled Pixel Extender

The SLM (130) of FIG. 1 may be equipped with pixels configured to reducethe stray light contribution to the modulated light (220) by separatingthe stray light (230) from the modulated light (220). FIG. 3Aillustrates an exemplary pixel (300) that includes an angled extender(320) attached thereto. The pixel (300) of FIG. 3A is representative ofa single pixel that may be arranged to form one or more pixel arrays.The pixel array(s) may be included as part of one or more integratedcircuit chips that form a part of the SLM (FIG. 1; 130) of the displaysystem (FIG. 1; 100).

The angled extender (320) may comprise any transparent orsemi-transparent material suitable for allowing enough light from thelight source (FIG. 1; 120) to pass through the angled extender (320) andreach the pixel (300). Enough light refers to any amount greater than orequal to a minimum amount of light that will allow the display system(FIG. 1; 100) to generate displayed images of acceptable quality. Theangled extender (320) may comprise but is not limited to transparent orsemi-transparent compositions of glass, plastic, and resin. The angledextender (320) may include coatings designed to manipulate itsreflective and/or refractive properties. In an exemplary embodiment, theangled extender (320) is in the form of a glass, wedge-shaped prism. Theangled extender (320) may be sized to approximately cover the topsurface of the pixel plate (350).

As shown in FIG. 3A, the angled extender (320) has a top surface (340)oriented, at a particular angle (A), toward the light source (FIG. 1;120). The angle (A) is a measure of the angle of the top surface (340)with respect to the upper surface (330) of the pixel (300). With the topsurface (340) of the angled extender (320) angled toward the lightsource (FIG. 1; 120), the pixel (300) is configured to reflect straylight at a direction that generally will not intersect the displayoptics (FIG. 1; 140). In several exemplary embodiments, it is preferablefor the angle (A) to be greater than about two degrees. Further, it maybe desirable that the angle (A) be at least ten degrees (10°) withrespect to the upper surface (330) of the pixel (300). According to thepresent exemplary embodiment the pixel (300) also includes a pixel plate(350) with a semi-reflective coating and a fixed, highly reflectivebottom electrode plate (360), which rests on a substrate (370). Thepixel plate (350) is supported above the electrode plate (360) by posts(380) and flexures (390).

In FIG. 3A, light rays (210) from the light source (FIG. 1; 120) travelto the pixel (300). As the light rays (210) reach the top surface (340)of the angled extender (320), a certain amount of the light rays (210)reflects off of the top surface (340) and travels, as stray light (230),away from the pixel (300), as generally shown in FIG. 3A Because of theangled top surface (340) of the angled extender (320), the stray light(230) is separated from the modulated light (220) such that the angledextender (320) minimizes the stray light (230) that mixes with themodulated light (220).

The transmitted light rays (210-1) travel through the angled extender(320) until reaching the top side of the pixel plate (350). At thisinterface, a small portion of the light incident on the pixel plate(350) will be reflected. The amount of light may be minimized byreducing a difference between the index of refraction of the angledextender (320) and the pixel plate (350) by using index-matchingadhesives. As the light rays (210) travel through the pixel plate (350),they are incident on the underside of the pixel plate (350), which maybe coated with a semi-reflective coating. An intermediate portion (395)of the transmitted light (210-1) is then reflected back through thepixel plate (350) and angled extender (320) and away from the displayoptics (140).

The non-reflected, or transmitted light (210-1) passes through the pixelplate (350) and the reflective coating and into the optical gap betweenthe pixel plate (350) and the electrode plate (360). Once the lightenters the optical gap, it is bounced between the partially reflectivecoating on the pixel plate (350) and the highly reflective coating onthe electrode plate (360). Each time the light inside the optical gapbecomes incident on the reflective coating on the underside of the pixelplate (350), a portion of modulated light (220) passes through thepartially reflective coating and pixel plate (350), through the angledextender (320), and escapes the pixel (300). The wavelength of themodulated light (220) that is thus able to escape depends, at least inpart, on the size of the optical gap, Accordingly, varying the size ofthe optical gap controls the characteristics of light that exits thepixel (300).

The angled extender (320) separates the modulated light (220) from thereflected light (230, 395). In particular, the exiting modulated light(220) travels through a section of the angled extender (320) that isthicker than the section of the angled extender (320) passed through bythe entering light rays (210-1). As the modulated light (220) exits fromthe angled extender (320), the modulated light (220) refracts fartheraway from the path of the stray light (230), thereby further separatingthe stray light (230) from the modulated light (220).

When multiple pixels (300) are arranged to form an array, each pixel(300) may function to increase the separation between the modulatedlight (220) and the stray light (230) as discusses above. FIG. 3Billustrates a perspective view of multiple exemplary pixels (300)arranged on an integrated circuit chip (360). As shown in FIG. 4, thepixels (300) may be arranged to form arrays of different sizes andshapes for different sizes and shapes of integrated circuit chips (360).

Angled Cover Plate

The contrast ratio of displayed images may also be improved byimplementing a cover plate designed to separate reflected stray lightfrom the modulated light (220). For example, FIG. 4 illustrates anangled, wedge-shaped cover plate (420) that may be positioned betweenthe light source (FIG. 1; 120) and a particular pixel (300-1). Like theangled extender (320), the cover plate (420) may comprise anytransparent or semi-transparent material suitable for allowing enoughlight from the light source (FIG. 1; 120) to pass through the coverplate (420) and reach the pixel (300). Again, enough light refers to anyamount greater than or equal to a minimum amount of light that willallow the display system (FIG. 1; 100) to generate displayed images ofacceptable quality. The cover plate (420) may include but is not limitedto transparent or semi-transparent compositions of glass, plastic, andresin. In an exemplary embodiment, the cover plate (420) is madesubstantially of a glass composition.

As shown in FIG. 4, the cover plate (420) has a top surface (440) angledtoward the light source (FIG. 1; 120). In such an angled position, thecover plate (420) is configured to reflect stray light (450) away fromthe display optics (FIG. 1; 140). When light rays (210) reach the topsurface (440) of the cover plate (420), a certain amount of the lightrays (210), referred to as the stray light (450), is reflected off ofthe surface (440) and away from the pixel (300-1).

The transmitted light rays (210-2) travel through the cover plate (420).Another portion of light (460) is reflected from the second surface ofthe cover plate (420) while the rest is transmitted light rays (210-2)that are directed to the pixel (300-1). The pixel (300-1) then modulatesand manipulates the light rays (210-2) to generate the modulated light(220), as discussed above. While a Fabry-Perot type pixel is discussedherein, those of skill in the art will appreciate that the cover plate(420) may also be used with any type of pixel array. Accordingly, forease of reference, the pixel (300-1) is illustrated schematically inFIG. 4.

The modulated light (220) is directed from the pixel (300-1) through thecover plate (420) and toward the display optics (FIG. 1; 140). The straylight (450) is reflected along a path that generally diverges from thepath of the modulated light (220). Consequently, the stray light (450)is generally prevented from mixing with the modulated light (220).

As shown in FIG. 4, the cover plate (420) may be in the shape of a wedgewith the thinner end of the wedge near the light source (FIG. 1; 120).With the thinner end of the cover plate (420) positioned near the lightsource (FIG. 1; 120), the cover plate (420) is configured to refractlight in a manner that further separates the stray light (450) from themodulated light (220). The light rays (210) from the light source (FIG.1; 120) refract, as designated by the light rays (210-2), upon entryinto the cover plate (420). In addition, the modulated light (220) exitsthe pixel (300-1) and travels through the cover plate (420).

Because the cover plate (420) is wedge-shaped, the exiting modulatedlight (220) travels through a section of the cover plate (420) that isthicker than the section of the cover plate (420) passed through by theentering light rays (210-2). As the modulated light (220) exits from thecover plate (420), the modulated light (220) refracts farther away fromthe path of the stray light (450), thereby further separating the straylight (450) from the modulated light (220).

The cover plate (420) may extend to cover multiple pixels (300) arrangedin one or more pixel arrays. In an exemplary embodiment, the cover plate(420) is arranged to cover the pixels (300) of a pixilated integratedcircuit chip.

Combination of Angled Extenders and Cover Plate

In several exemplary embodiments, the angled extenders (FIG. 3A; 320)and the cover plate (FIG. 4; 420) may be used together to cooperativelyincrease the separation between paths of the modulated light (FIG. 2;220) and paths of the stray light (FIG. 2; 230 and FIG. 4; 450). FIG. 5illustrates an exemplary segment (500) of an array of the pixels (300)covered by the cover plate (420). The pixels (300) and the cover plate(420) may be configured as described above.

As light rays (210) from the light source (FIG. 1; 120) reach the topsurface (440) of the cover plate (420), stray light (450) reflects offof the surface (440). As shown in FIG. 5, the stray light (450) isreflected generally away from the display optics (FIG. 1; 140).

The remainder of the light rays (210-2) travel through the cover plate(420) and toward the pixel (300). As the remaining light rays (210-2)reach the top surface (340) of the angled extender (320), stray light(230) reflects off of the top surface (340) and travels away from thepixel (300). As shown in FIG. 5, the stray light (230) travels throughthe cover plate (420), emerging from the top surface (440) of the coverplate (420) to travel generally along a path that does not intersect thedisplay optics (FIG. 1; 140). In this manner, the stray light (230)reflected form the surface (340) of the angled extender (320) isprevented from mixing with the modulated light (220).

The remainder of the light rays (210-3) not reflected off of the surface(340) of the angled extender (320) travel through the angled extender(320) until reaching the pixel (300). The light rays (210-3) are thenmodulated and manipulated within the pixel (300) to generate themodulated light (220). The modulated light (220) exits the pixel (300),travels through the angled extender (320), and toward the cover plate(420) as shown in FIG. 5. The modulated light (220) then travels throughthe cover plate (420), emerging from the top surface (440) of the coverplate (420) to travel generally along a path that generally intersectsthe display optics (FIG. 1; 140).

Thus, the respective angled surfaces (340 and 440) of the angledextender (320) and the cover plate (420) direct the reflected straylight (230 and 450) away from the display optics (FIG. 1; 140), therebyreducing the amount of stray light that might be mixed with themodulated light (220) at the display optics (FIG. 1; 140).

The modulated light (220) may be further separated from the reflectedstray light (230 and 450) by the respective wedge-shapes of the angledextender (320) and the cover plate (420). The modulated light (220)travels through segments of the angled extender (320) and the coverplate (420) that are relatively thicker than the segments of the angledextender (320) and the cover plate (420) through which the reflectedstray light (230 and 450) pass. As a result, the modulated light (220)is generally refracted farther away from the paths of the stray light(230 and 450), as shown in FIG. 5. With the increased separation betweenthe paths of the reflected stray light (230 and 450) and the modulatedlight (220), the amount of stray light mixed with the modulated light(220) is reduced, and image contrast is consequently improved.

Method of Reducing Stray Light Contribution

FIG. 6 is a flowchart illustrating an exemplary method of reducing straylight contribution to the modulated light (FIG. 2; 220) in the displaysystem (FIG. 1; 100). While FIG. 6 shows a number of steps of anexemplary method, in other embodiments, some of the steps may beomitted, additional steps may be performed, and/or the steps may beperformed in a different order than shown.

The method begins by implementing at least one pixel (step 610) in thedisplay system (FIG. 1; 100). In particular, one or more arrays of theexemplary pixels (FIG. 3A; 300) may be implemented in the SLM (FIG. 1;130) of the display system (FIG. 1; 100). The pixel arrays may beincluded as part of one or more integrated circuits, such as the pixel(FIG. 3A; 300) arranged on the integrated circuit (FIG. 3B; 360) of FIG.3B. An exemplary method of forming arrays of exemplary pixels (FIG. 3A;300) is discussed in detail below.

The pixels (FIG. 3A; 300) and the display optics (FIG. 1; 140) of thedisplay system (FIG. 1; 100) may be configured (step 620) so that thepixels (FIG. 3A; 300) are arranged to direct modulated light (FIG. 2;220) to the display optics (FIG. 1; 140). This may involve aligning anarray of the pixels (FIG. 3A; 300) with the display optics (FIG. 1;140), and taking into account the light refractions introduced by thewedge shape of the angled extender (FIG. 3A; 320) of the exemplary pixel(FIG. 3A; 300). In several exemplary embodiments, the configuration(step 620) may involve taking into account the light refractionsintroduced by the wedge shape of the cover plate (420; FIG. 4).

Light rays (FIG. 2; 210) may be projected at the implemented pixel (FIG.3A; 300) (step 630). The light source (FIG. 1; 120) is configured toproject the light rays (FIG. 2; 210). Modulated light (FIG. 2; 220) maybe formed from the projected light rays (FIG. 2; 210) (step 640). Thepixels (FIG. 3A; 300) of the exemplary pixels (FIG. 3A; 300) maymodulate the light rays (FIG. 2; 210) as discussed above. The modulatedlight (FIG. 2; 220) is reflected from the pixels (FIG. 3A; 300) anddirected toward the display optics (FIG. 1; 140).

Reflected stray light (FIG. 3A; 330 and FIG. 4; 450) is directed awayfrom the modulated light (FIG. 2; 220) (step 650). As discussed above,the angled orientation of the angled extender (FIG. 3A; 320) and/or theangled orientation of the cover plate (FIG. 4; 420) reflect the straylight (FIG. 3A; 330 and FIG. 4; 450) along paths that generally divergefrom the modulated light (FIG. 2; 220) and generally prevent thereflected stray light (FIG. 3A; 330 and FIG. 4; 450) from intersectingthe display optics (FIG. 1; 140).

One or more display images may be formed from the modulated light (FIG.2; 220) (step 660). The display optics (FIG. 1; 140) may prepare themodulated light (FIG. 2; 220) for display as discusses above. Thecontrast of the display images is improved because the stray light (FIG.3A; 330 and FIG. 4; 450) generally does not mix with the modulated light(FIG. 2; 220).

Method of Forming Arrays of Exemplary Pixels

FIG. 7 is a flowchart illustrating an exemplary method of forming anarray of exemplary pixels (FIG. 3A; 300) having angled extenders (FIG.3A; 320), according to one embodiment. While FIG. 7 shows a number ofsteps of an exemplary method, in other embodiments, some of the stepsmay be omitted, additional steps may be performed, and/or the steps maybe performed in a different order than shown.

The method begins by forming an array of angled extenders (FIG. 3A; 320)(step 710). The array may be of any size or shape and may include one ormore angled extenders (FIG. 3A; 320). For example, the array maycomprise a linear row or multiple rows of angled extenders (FIG. 3A;320). The size and shape of the array may be determined based on aparticular application or integrated circuit chip design. The array ofangled extenders (FIG. 3A; 320) may be produced using a sol-gel processcommonly used in creating glass and ceramic materials for diffractiveoptics testbeds.

The array of angled extenders (FIG. 3A; 320) may be index matched to anarray of pixels (FIG. 3A; 300) by selecting an index matching fluid oradhesive (step 720). Index matching refers to using an index matchingfluid or adhesive to bond the angled extenders (FIG. 3A; 320).

The array of angled extenders (FIG. 3A; 320) may be placed on the arrayof pixels (FIG. 3A; 300) such that the adhesive physically couples thearrays together (step 740). A precision robotic mechanism may be used toplace the array of angled extenders (FIG. 3A; 320) on the pixels (FIG.3A; 300).

In some embodiments, steps 710 through 740 may be repeated to placeadditional arrays of angled extenders (FIG. 3A; 320) on arrays of pixels(FIG. 3A; 300). For example, multiple arrays of angled extenders (FIG.3A; 320) in the form of individual rows may be placed row-by-row on anintegrated circuit of pixels (FIG. 3A; 300) by repeating steps 710through 740 for each row. Other sizes and shapes of arrays of angledextenders (FIG. 3A; 320) may be iteratively or non-iteratively places onarray of pixels (FIG. 3A; 300).

Either before or after the array of angled extenders (FIG. 3A; 320) isplaced on the array of pixels (FIG. 3A; 300). If desired, the angleextenders (FIG. 3A; 320) may be isolated from one another (step 750). Inone embodiment, a laser scribe is used to isolate the angled extenders(FIG. 3A; 320) from one another. In another embodiment, a pattern oflaser beams is lithographically exposed by creating a mask and imagingthe mask on an integrated circuit chip to break the connections betweenthe angled extenders (FIG. 3A; 320). The exemplary method of FIG. 7 maybe performed either at manufacture of components of the display system(FIG. 1; 100) or at a modification event subsequent to manufacture.

In conclusion, an exemplary pixel including a pixel and an angledextender is provided. The angled extender of the exemplary pixel mayimprove the contrast of images produced by a display system by reducingthe amount of stray light that mixes with modulated image-carryinglight. An angled surface of the angled extender reflects a portion oflight rays from a light source at an angle that helps to separate thereflected stray light from the modulated light reflected by the pixel.Consequently, the amount of stray light that mixes with the modulatedlight is reduced, and picture contrast of the display system may beimproved.

In several exemplary embodiments, an angled, wedge-shaped cover platemay be positioned between an integrated circuit of pixels and a lightsource. As light from the light source strikes the surface of the coverplate, stray light reflects from the surface at angles that move thestray light away from the modulated light reflected by the pixels.Consequently, the amount of stray light that mixes with the modulatedlight is reduced by the angled, wedge-shaped cover plate, and picturecontrast of the display system may be improved. The cover plate may beimplemented with or without the angled extenders of the pixels.

The preceding description has been presented only to illustrate anddescribe the present method and apparatus. It is not intended to beexhaustive or to limit the disclosure to any precise form disclosed.Many modifications and variations are possible in light of the aboveteaching. It is intended that the scope of the disclosure be defined bythe following claims.

1. A projector assembly, comprising: a spatial light modulator; a lightsource configured to direct light to said spatial light modulator;display optics configured to receive a spatially modulated light beamfrom said light modulator; and a plurality of angled extenders, eachangled extender being coupled to a pixel of said spatial lightmodulator, each of said angled extenders including a first surface; anda second surface, said second surface being configured to be placed inoptical communication with at least one pixel and being disposed at anangle relative to said first surface, wherein said angled extenders areconfigured such that light from said light source reflected by saidfirst surface is reflected away from said display optics, but lightmodulated by a pixel is directed by a said angled extender to saiddisplay optics.
 2. The angled extender of claim 1, wherein at least oneof said angled extenders has an angle of at least two degrees definedbetween said first surface and said second surface.
 3. The angledextender of claim 1, wherein each of said angled extenders is wedgeshaped.
 4. The angled extender of claim 1, wherein each of said angledextenders are arranged such that an thinnest end of said angled extenderis most proximate said light source.
 5. The assembly of claim 1, whereinsaid angle is from 2 to 10 degrees.
 6. The assembly of claim 1, furthercomprising a separate angled extender corresponding and coupled to eachsaid pixel of said spatial light modulator.
 7. The assembly of claim 1,further comprising a cover plate covering said spatial light modulatorand said plurality of angled extenders, wherein said cover plate is alsoconfigured such that light from said light source reflected by a firstsurface of said cover plate is reflected away from said display optics,but light passing through said cover plate which is then modulated by apixel is directed by a said cover plate to said display optics.
 8. Theassembly of claim 1, wherein said angled extenders each comprise aprism.
 9. The assembly of claim 1, wherein said angled extenders arecoupled to said pixels using an adhesive that matches an index ofrefraction of said angled extender with an index of refraction of apixel plate of a said pixel.
 10. The assembly of claim 1, wherein eachsaid pixel is configured to use internal reflection to produce light ofa specific color.
 11. A projector assembly, comprising: a spatial lightmodulator having a plurality of pixels; a light source in opticalcommunication with said pixels; display optics configured to receive aspatially modulated light beam from said light modulator; and an angledextender having a first surface and a second surface, said secondsurface being configured to be placed in optical communication with saidpixels and being disposed at an angle relative to said first surface,wherein said angled extender comprises a cover plate covering saidspatial light modulator, wherein said cover plate is configured suchthat light from said light source reflected by a first surface of saidcover plate is reflected away from said display optics, but lightpassing through said cover plate which is then modulated by a pixel isdirected by a said cover plate to said display optics.
 12. The assemblyof claim 11, further comprising a plurality of additional angledextenders disposed between said cover plate and said pixels of saidspatial light modulator, wherein said plurality of additional angledextenders are placed in optical communication with said plurality ofpixel, wherein said angled extenders are each configured such that lightfrom said light source reflected by an upper surface of an angledextender is reflected away from said display optics, but light modulatedby a pixel is directed by a said angled extender to said display optics.13. The assembly of claim 12, wherein each of said plurality ofadditional angled extender comprises a prism.
 14. The assembly of claim11, wherein each said angled extender corresponds to and is coupled toone of said plurality of pixels.
 15. The assembly of claim 11, whereinsaid plurality of pixels comprise Fabry-Perot type pixels.
 16. Theassembly of claim 11, wherein said plurality of pixels comprisereflective type pixels.
 17. The assembly of claim 11, wherein said angleis from 2 to 10 degrees.
 18. The assembly of claim 11, wherein saidangled extenders are coupled to said pixels using an adhesive thatmatches an index of refraction of said angled extender with an index ofrefraction of a pixel plate of a said pixel.
 19. The assembly of claim11, wherein said cover plate coupled to said pixels using an adhesivethat matches an index of refraction of said cover plate with an index ofrefraction of a pixel plate of a said pixel.
 20. The assembly of claim11, wherein said cover plate has a wedge shape.
 21. The assembly ofclaim 11, wherein said cover plate is arranged such that a thinnest edgeof said cover plate is arranged most proximate to said light source. 22.The assembly of claim 11, wherein each said pixel is configured to useinternal reflection to produce light of a specific color.